maximum number of curves?

nilsoberg · Post by **nilsoberg** » Tue Mar 01, 2005 1:22 pm

Hi!

I'm plotting a lot of curves, possibly 200+ on one plot. When I attempt to plot more than 100 curves using Dplot Jr., in C++, I get the following message:

The instruction at "0x..." referenced memory at "0x...". The memory could not be "read".

Either 20 seconds later or as soon as I press the "OK" button in the aforementioned dialog box, I get this:

Timeout error, current timeout value=20000 msec

Each curve has a maximum of 132 points on it. For one case, there are 134 curves, and the x/y arrays are allocated with for 17688 cells.

It works well for <=100 points. Any ideas on what is going on?

Thanks!

Nils

Post by **DPlotAdmin** » Tue Mar 01, 2005 1:43 pm

I'm plotting a lot of curves, possibly 200+ on one plot. When I attempt to plot more than 100 curves using Dplot Jr., in C++, I get the following message:

The instruction at "0x..." referenced memory at "0x...". The memory could not be "read".

I didn't bother trapping number of curves > 100 because I thought the limit was fairly obvious in the header file. Of course it's obvious to me, but I should have been more thorough. I'll add a check for this in the next release.

But that doesn't really address your problem: you want more than 100 curves. I guess I'd be more likely to change the limit if I could be made to understand that this would be a useful change. I can't picture a graph with >100 curves that wouldn't be... a mess.

nilsoberg · Post by **nilsoberg** » Tue Mar 01, 2005 2:03 pm

In my plots I have two types of curves, upwards-curving and downwards-curving. They converge to nearly the same point, but start out at slightly different locations. They all have the same shape. The idea is that the plot is a graphical snapshot of a data file that allows the user to verify that numbers generated by an interpolation program are more or less correct. See the plot linked to below.

Thanks!

Nils

Post by **DPlotAdmin** » Tue Mar 01, 2005 2:15 pm

Thanks for the example, and yes I can see the light now.

I'll add this to the to-do list, but it might be a while before this is ready. It will require changes to the DPLOTLIB interface (no problem), changing one number and recompiling DPlot (again, no problem) and re-working a dozen or so dialog boxes and dialog procedures that are set up for no more than 100 curves (and there's where the bit of a problem lies).

Will probably change the limit to a nice geek number like 256. And the next day somebody will want 257

nilsoberg · Post by **nilsoberg** » Tue Mar 01, 2005 2:22 pm

Thank you!

Nils

Peter Simmonds · Post by **Peter Simmonds** » Sat Mar 12, 2005 3:40 am

Hi

Just as an additional request, if you do change the maximum number of curves, can you possibly make it more than 255? I have an application that really needs to plot about 500 graph lines, and have had obvious problems with other graphing methods such as Excel (maximum 255). Standalone graph drawing packages that I have have tried also seem to have strange arbitrary low limitation.

The type of graph that Nils sent is quite common and not really catered for in existing packages as far as I have been able to find.

His other point, that there should be a different method for assigning colours to the curves is also really important, should be possible to set curves 1-34 as Red, 35-88 as Blue etc.

Peter

Post by **DPlotAdmin** » Sat Mar 12, 2005 10:30 am

The maximum number of curves will be increased. Just thinking out loud: The only real problem is picking a limit. (And yeah there has to be one to make all of the DPLOTLIB stuff work with all languages.) And it would be nice to change the limit once to a number that will please everyone (HA!

). Anyhow... this will definitely get done, but not in the next release. Several dialogs need to be reworked and I need to rearrange how several things are allocated so I don't end up wasting more memory than I have to.

Unique colors per curve is done and will be in the next release.

Peter Simmonds · Post by **Peter Simmonds** » Sun Mar 13, 2005 5:54 am

David, thanks! Look forward to the next version(s).

As a new user, would just like to say the plotting program looks great, and very easy to use through PowerBasic Console Compiler (which as you may know is a bit lacking in graphics!).

Peter